This is a library of perfboard and single-sided PCB effect layouts for guitar and bass. I'm not an electrical engineer by any stretch of the imagination, just a DIY'er who likes drawing layouts. It is meant for the hobbyist (so commercial use of any of these layout is not allowed without permission) and as a way to give back to the online DIY community.

Monday, July 25, 2016

One-Knob Noise Gate

Found this one over on the Tagboard forum and thought it would be a good addition here. It's a simple noise gate with minimal parts count that can easily fit in a 1590a. I've laid it out for a board mounted pot. The schematic calls for a 1M pot, but people have built this using one as low as 25k, so experiment there. The original schematic was a little hard to read so I redrew it.


70 comments:

  1. A pair of BC550 will work ok?

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  2. I would think so. That's what I would sub.

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  3. yay!!! let's make one, coz our mxr noise gate didn't work
    awesome as usual brother.
    still finding way to donate though...

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  4. ah, one question,
    will rotated 2n7000 for bs170 do?

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  5. can i use j201 or 2n5457 instead of the bs170????

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    1. No, that needs to be a MOSFET, not a JFET. BS170 or 2N7000 are your best bet.

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  6. You can use BSS296 or 2SK422 , pinning attention? Another detail and that the gain of the 2N7000 and a little less than the BS170 , will have to reverse also the 2N7000 .

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  7. Spectacular! Just in these days I was drawing exactly the same diagram, but you did first, great!
    How you can mod it to control the decay
    or attack of the gate?
    Greetings from Argentina!

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    1. Diego! Lo arme y asi como figura aca funciona muy bien. Le puse un LPB-1 antes y ahi si que quedo excelente, tiene un muy buen desempeño. Estaba buscando la misma mod que vos, pero nada (convengamos que no soy un Einsten en esto y que lo arme hace pocos dias :P). Si descubriste algo y podes compartirlo, seria genial! Abrazo papa!

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    2. This comment has been removed by the author.

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    3. Hello, I found this topic in the diystomboxes forum.
      Kipper4 solution is good.
      I hope it works for you
      http://www.diystompboxes.com/smfforum/index.php?topic=114229.0

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    4. Diego, como estas? Vos sabes que yo arme este mismo... pero puede ser q funcione bien cuando viene con ganancia? O sea le conecto solo la guitarra con un simple bobina para q haga zumbido y no lo corta.... lo probaste con pote de 1 mega o 25 k? Saludos!

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  8. I used 2n7000 and 2n3904 for Bjt's .. thanks PCB layoutsb:D greetings From Philippines

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    1. Pag gamit ka 2n7000 at 2n3904 need i rotare lahat? Btw how's the sound?

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  9. All transistors should be rotated in 180 deg.

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    1. Why? I have all the parts installed as shown above and signal passes but I don't think it is gating the sound. Nothing changes when I turn the pot all the way clockwise. All sound drops drastically when the pot is all the way counterclockwise.

      Why do you say rotate the transistors?

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  10. my build is working correctly. but the pot, A1M, I don't get any change when I turn it up and down. It also reduces my overall volume a little bit.
    any idea?

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    1. See the post about the pot value and it might just benefit from a buffer in front of it.

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    2. I am the same as several people speaking, nothing happens. I can understand that silence failed when switching on, but nothing happens, same as when off. If you are successfully verified, please advise me.

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  11. While i'm waiting for a pair of bs170 i've tried with an irf520 but it doesn't nothing with the sound, it's still the same. That mosfet by the way, has almost the same values than bs170.... What should be the problem????

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  12. Built but it is effecting the tone quite a bit. When using a clean sound, its sounding slightly distorted. I'm using 2 BC550's and a BS170 as my trannies. Any ideas or does that explain why most noise gate circuits are much much bigger?

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  13. Verified! It works really great with a buffer or a booster in front of it. Nice work guys!

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  14. Hello! thank you all for your contributions. I have learned a lot by building several pedals here.
    Now a question. What is the function of diodes 5718 ?, since in the schematic does not appear. Greetings from Argentina.

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    1. That's just there for polarity protection. If you accidentally plug in a power supply that is positive ground, that diode with keep the circuit safe.

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  15. Thank you very much for your reply. So, can this diode be replaced by a diode 1n4001 or similar? Thank you very much again.

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    1. Yes, a 4001 will work, but will drop a little more voltage than the 5817. But it shouldn't be a big deal.

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  16. Thank you very much everyone for the responses.

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  17. HI! Thanks for amazing site with a lot of great schematics. I'm new in diy and this is my second effect, and I have a problem with it.
    I did it on pcb version with the same components such on layout, but when I turn up pot, it starts gating immediately and stop it in a second (or few), this happens when turn pot up, when it turn down - nothing happened. Please help me to find a problem. Sorry for bad English.

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  18. UPD: When I'm playing, it turns on gating every 10-15 seconds on few seconds again.
    Can problem be in some of capacitors? Or something else?

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  19. Hi!

    This thing works like a charm in my amps FX loop.
    Kinda on/off, will box it without the B1M.
    Does what it's supposed to and good.

    Thanks!

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  20. Works fine, but when it opens to let signal pass a "click" is heard. Use bs549 and bs170 and potentiometer of 25k. Is there any way to fix that "click", Thank you

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    1. The most classical way to avoid a "poc" when switching is to put a "high" value polarised cap (minimum 22uf) between the V+ and the V- (or ground). I've already add one directly to the power supply socket with success; it works like that too.

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  21. Hello Effects Layouts. I was just wondering why do the schematic and layout have some differences? The layout has a 220nF capacitor, but the layout has a 47uF one. Also on the schematic there's only 2 diodes but the layout has 3, adding a 5817.

    Could you help a beginner understand what's going on? Thanks!

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    1. The extra diode is for polarity protection and the 47uF cap is for power filtering. The 220nF cap is consistent with the schematic and layout.

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  22. Hello …
    where is the layout ? Can't find it in the "O" folder …
    Thx

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  23. very good noise gate !! works very good !

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  24. It sound a click when is gating, how can I fix it? Maybe putting 1M resistor between In and ground?

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  25. A little confused about polarity of the 10uF cap. Schematic and Savas' layout on tagboardeffects have the input going to +'ve of cap and gate 1. Other layouts on that site and the one here have input going -'ve of cap and gate 1.
    could this account for some experiencing odd or no effect from Gate pot?
    Which polarity of the 10uF is correct do you think?

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    1. In my experience, with polarized caps at the input with center negative effects, the positive side goes towards the transistor. If you're getting noise though, feel free to flip that cap. Might work.

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  26. OK. Will have a fiddle. Thanks for all the good work you do here.

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  27. Great little circuit. I used a 250KB pot with best result on my DIY high gain tube amp (approx. 20 watt) at 75% volume about 60% gain. Over that and it should have at least a 500k pot or higher. Thanks John

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  28. I couldn't get mine to work, I etched and built it 2 times and even did the perf board version with no success. And then I switched the BS170 for a J201 and bam! Worked right away, even with the 1M (though I've swapped it for a 250K). I had the same issue with the mxr noise gate and the J201 swapped worked on it too. Hope this helps

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  30. I built mine to decrease the noise in the crunch channel of a Peavey 112 (Is connected on the effect loop) but it only works when the volume is higher than 40%... Any ideas on how to resolve this? No components have been replaced..

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  31. I tried it and works well with 25k pot.
    This circuit is severely affected by the individual differences of the transistors' hfe, I expect.

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  32. I made this circuit using a B100k pot.It works really nice after my overdrive pedal,than it goes straight into a high gain tube amp.Thanks for the layout.

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  33. Built this one. Disappointed. It pretty much requires a buffer in front of it, otherwise you'll get a volume drop and distortion (and even with a buffer there's a slight crunchiness to it). I found on my build that a 1m pot was way overkill - even the lowest level gated a bit too much. 100k is probably good. Built with a BS170 and a pair of BC550C (HFE a little over 500).

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    1. After playing with it a bit longer, I think it's adequate in an effects loop, but not on it's own with a guitar plugged straight in. It's still a bit crunchy, but it seems fine on dirty guitar at least.

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    2. What transistors did you use?

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  34. I might as well try this one.. long live!
    Jun from Philippines

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  35. I just build it few hours ago and it works! 2n3904 and 2n7000 can be used perfectly!
    Jun fr Philippines

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    1. Hi Jun, I used the same transistors as you did and oriented them correctly. But I think the gating is always “on” since the entire volume drops when I engage it even when the pot’s all the way down. Do you have an idea where I might’ve went wrong? Triple checked my components all are fine. Greetings from the Ph as well!

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  36. Hi, I can't make it work right. Using a B1M has no effect when i move the pot. I always suppress the same. Also tried with 500k (same result) and 25k (this one has a no sound result). With 1M also has too low volumen, you can't even hear the sound coming from the guitar.
    Any ideas?

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  37. Hi. I'm looking at the circuit and i notice that some electrolitic capacitors are inverted compared to the same circuit in other sites. Are they verified?
    Thanks a lot! I love this site!!!

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    1. Hello, can you pass me a link of those circuits that you mention?
      I would like to compare and test
      thank you

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  38. hello everyone, does this project work?
    Is there any schematic or layout with improvements that can help me build it?

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  39. Where do I get the image to record the pcb?

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  40. why it doesn't work? I've been three times to making this Noise Gate. But, still doesn't working. I put 1M pots (still not) and use 25K pots (still not working). I use BS170, 1N4148, 1N5817 as the pic and use all of same resistor value that need. And the one that I got frustrated is, my guitar sound has no signal to amplifier after I turn on this pedal. Any idea to fix this problem? I really need NOISE GATE, if you can show me what should i do.. I really big thanks to you.. ;)

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